Research laboratories that use monkeys usually house them in relatively small cages with one or two monkeys per cage (cage housing) or in a large room or large cage with many monkeys present (gang housing). These two methods constitute the two principal methods that are now in use for housing of monkeys. Each method has its advantages and disadvantages. When monkeys are housed in individual cages they have little room to move about or climb and, if there is only one monkey in the cage, there is no opportunity for social contact. If two monkeys are kept in one cage there is social contact, but this is achieved at the expense of crowding. Cage housing has an advantage over gang housing in that the monkeys are easily caught for injections, examination, removal or other experimental procedures. Gang-housing on the other hand provides social contact and room to move about and climb. However the monkeys are not readily accessible to the experimenter; catching a monkey is difficult, requiring entrance into the gang cage and chasing the monkey with a net or trying to catch it while wearing gloves.
The present invention overcomes some of the deficiencies of cage and gang housing. The invention is comprised of a number of climbing poles to which the monkeys can be attached by tethers. One end (the first end) of the tether is attached to a collar around the monkey's neck; the other end of the tether (the second end) is attached to a loosely fitting ring that can slide up and down the pole as the monkey climbs up and down. Monkeys restrained on my device can climb up an down the poles, can make social contact with three to five adjacent monkeys, can obtain food and water at any time, and can be caught easily for injections, examinations, or other experimental procedures. The tethers are of such a length that the monkeys cannot become entangled with each others tethers.